Viessmann LB1 - Page 42

42
Cause Measure
High limit safety cut-out on electric preheating coil has
responded.
Check electric preheating coil. Replace preheating coil
if required.
Replace the thermal breakers.
14 Supply air fan
Both fans are stopped.
Cause Measure
Supply air fan blockage, fault or signal interruption
■
Check fan for blockage or contamination. Remove
any blockages. Clean fan.
■
Check fan electrical connections and connecting ca-
ble.
■
Check fan is mechanically and electrically sound.
■
Replace fan if required.
■
Remove the power supply plug, then plug it back in.
15 Exhaust air fan
Both fans are stopped.
Cause Measure
Exhaust air fan blockage, fault or signal interruption
■
Check fan for blockage or contamination. Remove
any blockages. Clean fan.
■
Check fan electrical connections and connecting ca-
ble.
■
Check fan is mechanically and electrically sound.
■
Replace fan if required.
■
Remove the power supply plug, then plug it back in.
16 Bypass damper
Bypass damper does not open or close.
Cause Measure
Bypass damper motor faulty Check electrical connections on the bypass damper
motor. Replace motor if necessary.
D0 Standby mode
Cause Measure
Fans in standby mode Increase the ventilation level.
D1 RTC communication
Cause Measure
Internal programming unit fault Restart the programming unit.
If the fault recurs, replace the programming unit.
Troubleshooting
Message list Vitovent 200-C (cont.)
5816558
Diagnosis